Spinal implants can be engaged to or along one or more vertebrae of the spinal column for the treatment of various spinal conditions. Fasteners can be provided to secure the implant to a particular location along the spinal column. The implants can be provided to stabilize the spinal column for treatment, either by fixing the spinal column or by permitting at least some motion of the stabilized motion segments.
Coupling assemblies such as multi-axial and uni-axial screws have been employed for securing elongated implants, such as rods or plates, along one or more motion segments of the spinal column. Such screws can comprise many components or parts to secure the implant to the screw that make placement and manipulation of the implant and screw during surgery cumbersome. The interaction between the components of these screws and the elongated implant and the complex spinal anatomy can result in less than optimal orientation and engagement between the components extending along the spinal column. Adjustable coupling assemblies that accommodate the spinal anatomy and the orientation between components and the implants are thus desirable to provide an optimum fit between the components and implant.